Method of and apparatus for melting and casting metals



J. H. L. DE BATS.

METHOD OF AND APPARATUS FOR MELTING AND CASTING METALS.

APPLICATION HLED MAR. 27, 1919.

Patented Sept. 28, 1920.

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Jmn'nu'nnnr LOUIS DE BATS, or s'ronnnm, MASSACHUSETTS, Assionon r mew rnocnss METALS. CORPORATION, or WILMINGTON, DELAWARE, A communion OF DELAWARE.

METHOD OF AND APPARATUS FOR MELTING AND CASTING METALS.

Specification of Letters Patent. Patefited Sept. 28, 1920.

Application filed March 27, 1919. Serial No. 285,609.

To all whom it may concern Be it known that I, JEAN HUBERT LOUIS DE BATS, a subject of the Kingdom of Netherlands, residing at Stoneham, county of Middlesex, Commonwealth of Massachusetts, have invented certain new and useful Improvements in Method of and Apparatus for Melting and Casting Metals, of which the following is a specification.

, tratlve drawing,

The object of my invention is to melt and cast metals under such conditions that they will not absorb oxygen or any other gas during the melting and casting operations, and will therefore be free from blow-holes,

specks, or chemically produced bodies, re-

sulting from combination with oxygen or other gases, or affected, so far as crystallization is concerned, by the presence of such oxygen or other gases.

To carry my improved method into effect, I may use any suitable apparatus whereby the necessary heat to bring about melting, is present, and where the melting and casting will take place without the inclusion of oxygen or other gases.

The accompanying drawing shows such an apparatus as may be employed, in which- Figure 1 is a sectional elevation showing a crucible containing melted metal ready to be poured into a mold.

Fig. 2 is a vertical section on the line II-II of Fig. 1, and showing the crucible raised so thatthe contents can be exposed to heating means.

Fig. 3 is a horizontal section on the line III-III of Fig. 2, and showing the crucible lowered to the position shown in Fig. 1.

Fig. 4 is a vertical section on the line IVIV of Fig. 2.

I wish it understood that the drawing is not intended to show the apparatus in all its operative details, but merely as an illuspartially diagrammatic, of an apparatus which will carry the invention into efiect.

Referring to the drawing, 5 indicates a melting chamber where the temperature is produced by the heat of an electric current by the use of an arc, as shown in the drawing. Instead of an arc furnace, a radiation furnace or any other type of electric furnace may be employed. Instead of an electric furnace, a gas-fired furnace may be used, provided the required temperature can be obtained, and irrespective of whether an electric furnace or gas furnace is used, a reducing atmosphere is present, or alternatively, instead of using a reducing atmosphere, an atmosphere of any gas which will not combine with the metal under treatment, may be employed, such for instance, as a nitrogen gas introduced through the pipe 6, from tank 7 IVhatever the gas, whether produced by the action of the arcs or by combustion of a fuel, or from an external source, the pressure of the gas within the furnace chamber should be suflicient to exclude the entrance of the external air. 8-9 indicate electrodes connected to any suitable source of electricity.

Situated in chamber The bottom 11 of the vertically adjustable by means of a hydraulic cylinder 12. The crucible is mounted on the top of the bottom of the chamber. The bottom of the chamber coacts with the walls of the chamber through a sand seal 13. When the melting operation is complete, the bottom 11 of the chamber is dropped into the extension 14 of chamber 5. This extension has connected to it, a casting chamber 15, provided with a door 16, and in which is placed a mold l7. Projecting through the side walls of the extension 14 is a pipe 18 and on the inner end of this pipe a pair of arms 19 are mounted, adjustable as regards each other through a screw 20, which arms are adapted to grasp the crucible 10 when the crucible is in the lowest position in the extension 14. On the other end of the pipe 18 is a bar 21, working through a sector on which is a lock-nut, so that when the bar reaches any defined position it may be locked. Connected to the upper end of the casting chamber 15, is a pipe 22 connected to a vacuum pump 23. 24 indicates a door in said extension 14.

y improved method may be carried out in the following manner: The material to be melted is introduced into the crucible 10. The material may be a metal, a combination of metals, or a combination of metals and chemicals, depending upon what product it is desired to produce. The crucible is then placed on the movable bottom 11 of the chamber 5, when the bottom is in the lowest position in the chamber 14, as at A. The bottom is then raised under the action 5 is a crucible 10.

of the hydraulic cylinder 12 into the position indicated at B, and subjected to electric or other heat until the metal is in a sufficiently fluid condition, the body of' the chamber 5 at such time containing a reducing atmosphere or non-oxidizing gas. When the melting operation is fully completed, the bottom 11 is dropped to the position indicated at When in this position, the crucible 10 is grasped by the arms 19 and the crucible is ready to pour. In the meantime, the air pump 23 has exhausted the air from the extension 14 and casting chamber 15, and when the bottom 11 is depressed to the position indicated at A, exhausts the air in the chamber 5. When the proper vacuum has 1 been obtained, the crucible 10 is tilted and the fluid metal therein passed into the mold 17.

In place of using the air pump 23 to exhaust the air, gas under pressure may be introduced through the pipe 6 into the chamber 5, and flowing into the extension 14 and casting chamber 15, drive out the air contained in this chamber so that the whole cavity of the apparatus will contain a nonoxidizing gas under pressure. As soon as the pressure reaches the required amount to exclude the external air, the pouring of the crucible may take place.

I am aware that it has heretofore been suggested to cast metal into a mold from which the air has been exhausted. The effect of exhausting the air is merely to cause the metal to flow into the finer parts of the mold. My invention differs from this, in, that the pouring is in a vacuum, with the mold in the vacuum. Consequently, the metal when poured, is in the best condition and is not subject to the action of such oxygen or combining gases. It therefore pours freely, does not take on'a ropey condition, and enters all spaces in the mold.

What I wish to have understood is, that my method difi'ers radically from a method which involves, first melting in an'electric or other furnace, then taking the material out of the furnace where it is oxidized by the atmosphere, then pouring in a moldwhere the interior of the mold is in a vacuum.

In such method, the material melted is subject to the action of the air, my method differing in that the metal from the time it is exposed to the heat, up to the time it is cast, is not exposed to the action of the air or any gas which will affect either its temperature, chemical composition, or structural characteristics.

Having thus described my invention, I claim:

1. The method herein described which consists in melting in an inert atmosphere as regards the material under treatment as to wholly'or partially prevent escape of occluded gases and then casting in an atmosphere maintained inert as regards the molten metal.

2. The method herein described which consists in melting and casting in a single integral structure from'which air is excluded.

3. The method herein described which consists in melting in an electric furnace in which a non-combining atmosphere is maintained and then casting in a chamber from which the air is excluded, and without exposing the heated metal between the two operations to the action of the atmosphere.

4:. The method herein described which consists in subjecting the metal to a continuously applied high temperature in an inert temperature and when melted casting the metal into a mold located in a substantial vacuum and without exposing the metal between the melting and casting operations, to the action of the atmosphere.

5. The method herein described which consists in melting and casting in a gas inert as regards the material under treatment, and under conditions where the pressure of the gas will prevent atmospheric air from being brought into contact with the material during melting and casting.

In testimony whereof I aflix my signature.

JEAN HUBER'I LOUIS DE BATS. 

